summaryrefslogtreecommitdiff
path: root/src/gallium/drivers/nv50/nv50_pc_regalloc.c
blob: d45dd7f95f5bbe627ecbe6e5de0bf972d4a9c999 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
/*
 * Copyright 2010 Christoph Bumiller
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "nv50_context.h"
#include "nv50_pc.h"

#include "util/u_simple_list.h"

#define NUM_REGISTER_FILES 4

struct register_set {
   struct nv_pc *pc;

   uint32_t last[NUM_REGISTER_FILES];
   uint32_t bits[NUM_REGISTER_FILES][8];
};

struct nv_pc_pass {
   struct nv_pc *pc;

   struct nv_instruction **insns;
   int num_insns;

   uint pass_seq;
};

static void
ranges_coalesce(struct nv_range *range)
{
   while (range->next && range->end >= range->next->bgn) {
      struct nv_range *rnn = range->next->next;
      assert(range->bgn <= range->next->bgn);
      range->end = MAX2(range->end, range->next->end);
      FREE(range->next);
      range->next = rnn;
   }
}

static boolean
add_range_ex(struct nv_value *val, int bgn, int end, struct nv_range *new_range)
{
   struct nv_range *range, **nextp = &val->livei;

   for (range = val->livei; range; range = range->next) {
      if (end < range->bgn)
         break; /* insert before */

      if (bgn > range->end) {
         nextp = &range->next;
         continue; /* insert after */
      }

      /* overlap */
      if (bgn < range->bgn) {
         range->bgn = bgn;
         if (end > range->end)
            range->end = end;
         ranges_coalesce(range);
         return TRUE;
      }
      if (end > range->end) {
         range->end = end;
         ranges_coalesce(range);
         return TRUE;
      }
      assert(bgn >= range->bgn);
      assert(end <= range->end);
      return TRUE;
   }

   if (!new_range)
      new_range = CALLOC_STRUCT(nv_range);

   new_range->bgn = bgn;
   new_range->end = end;
   new_range->next = range;
   *(nextp) = new_range;
   return FALSE;
}

static void
add_range(struct nv_value *val, struct nv_basic_block *b, int end)
{
   int bgn;

   if (!val->insn) /* ignore non-def values */
      return;
   assert(b->entry->serial <= b->exit->serial);
   assert(b->phi->serial <= end);
   assert(b->exit->serial + 1 >= end);

   bgn = val->insn->serial;
   if (bgn < b->entry->serial || bgn > b->exit->serial)
      bgn = b->entry->serial;

   if (bgn > end) {
      debug_printf("Aieee! BLOCK [%i, %i], RANGE [%i, %i)\n",
                   b->entry->serial, b->exit->serial, bgn, end);
   }
   assert(bgn <= end);

   if (bgn < val->insn->serial)
      debug_printf("WARNING: leaking value %i ?\n", val->n);

   add_range_ex(val, bgn, end, NULL);
}

#ifdef NV50_RA_DEBUG_JOIN
static void
livei_print(struct nv_value *a)
{
   struct nv_range *r = a->livei;

   debug_printf("livei %i: ", a->n);
   while (r) {
      debug_printf("[%i, %i) ", r->bgn, r->end);
      r = r->next;
   }
   debug_printf("\n");
}
#endif

static void
livei_unify(struct nv_value *dst, struct nv_value *src)
{
   struct nv_range *range, *next;

   for (range = src->livei; range; range = next) {
      next = range->next;
      if (add_range_ex(dst, range->bgn, range->end, range))
         FREE(range);
   }
   src->livei = NULL;
}

static void
livei_release(struct nv_value *val)
{
   struct nv_range *range, *next;

   for (range = val->livei; range; range = next) {
      next = range->next;
      FREE(range);
   }
}

static boolean
livei_have_overlap(struct nv_value *a, struct nv_value *b)
{
   struct nv_range *r_a, *r_b;

   for (r_a = a->livei; r_a; r_a = r_a->next) {
      for (r_b = b->livei; r_b; r_b = r_b->next) {
         if (r_b->bgn < r_a->end &&
             r_b->end > r_a->bgn)
            return TRUE;
      }
   }
   return FALSE;
}

static int
livei_end(struct nv_value *a)
{
   struct nv_range *r = a->livei;

   assert(r);
   while (r->next)
      r = r->next;
   return r->end;
}

static boolean
livei_contains(struct nv_value *a, int pos)
{
   struct nv_range *r;

   for (r = a->livei; r && r->bgn <= pos; r = r->next)
      if (r->end > pos)
         return TRUE;
   return FALSE;
}

static boolean
reg_assign(struct register_set *set, struct nv_value **def, int n)
{
   int i, id, s;
   uint m;
   int f = def[0]->reg.file;

   s = n << (nv_type_order(def[0]->reg.type) - 1);
   m = (1 << s) - 1;

   id = set->last[f];

   for (i = 0; i * 32 < set->last[f]; ++i) {
      if (set->bits[f][i] == 0xffffffff)
         continue;

      for (id = 0; id < 32; id += s)
         if (!(set->bits[f][i] & (m << id)))
            break;
      if (id < 32)
         break;
   }
   if (i * 32 + id > set->last[f])
      return FALSE;

   set->bits[f][i] |= m << id;

   id += i * 32;

   set->pc->max_reg[f] = MAX2(set->pc->max_reg[f], id + s - 1);

   id >>= nv_type_order(def[0]->reg.type) - 1;

   for (i = 0; i < n; ++i)
      if (def[i]->livei)
         def[i]->reg.id = id++;

   return TRUE;
}

static INLINE void
reg_occupy(struct register_set *set, struct nv_value *val)
{
   int s, id = val->reg.id, f = val->reg.file;
   uint m;

   if (id < 0)
      return;
   s = nv_type_order(val->reg.type) - 1;
   id <<= s;
   m = (1 << (1 << s)) - 1;

   set->bits[f][id / 32] |= m << (id % 32);

   if (set->pc->max_reg[f] < id)
      set->pc->max_reg[f] = id;
}

static INLINE void
reg_release(struct register_set *set, struct nv_value *val)
{
   int s, id = val->reg.id, f = val->reg.file;
   uint m;

   if (id < 0)
      return;

   s = nv_type_order(val->reg.type) - 1;
   id <<= s;
   m = (1 << (1 << s)) - 1;

   set->bits[f][id / 32] &= ~(m << (id % 32));
}

static INLINE boolean
join_allowed(struct nv_pc_pass *ctx, struct nv_value *a, struct nv_value *b)
{
   int i;
   struct nv_value *val;

   if (a->reg.file != b->reg.file ||
       nv_type_sizeof(a->reg.type) != nv_type_sizeof(b->reg.type))
      return FALSE;

   if (a->join->reg.id == b->join->reg.id)
      return TRUE;

#if 1
   /* either a or b or both have been assigned */

   if (a->join->reg.id >= 0 && b->join->reg.id >= 0)
      return FALSE;
   else
   if (b->join->reg.id >= 0) {
      if (a->join->reg.id >= 0)
         return FALSE;
      val = a;
      a = b;
      b = val;
   }

   for (i = 0; i < ctx->pc->num_values; ++i) {
      val = &ctx->pc->values[i];

      if (val->join->reg.id != a->join->reg.id)
         continue;
      if (val->join != a->join && livei_have_overlap(val->join, b->join))
         return FALSE;
   }
   return TRUE;
#endif
   return FALSE;
}

static INLINE void
do_join_values(struct nv_pc_pass *ctx, struct nv_value *a, struct nv_value *b)
{
   int j;
   struct nv_value *bjoin = b->join;

   if (b->join->reg.id >= 0)
      a->join->reg.id = b->join->reg.id;

   livei_unify(a->join, b->join);

#ifdef NV50_RA_DEBUG_JOIN
   debug_printf("joining %i to %i\n", b->n, a->n);
#endif
   
   /* make a->join the new representative */
   for (j = 0; j < ctx->pc->num_values; ++j) 
      if (ctx->pc->values[j].join == bjoin)
         ctx->pc->values[j].join = a->join;

   assert(b->join == a->join);
}

static INLINE void
try_join_values(struct nv_pc_pass *ctx, struct nv_value *a, struct nv_value *b)
{
   if (!join_allowed(ctx, a, b)) {
#ifdef NV50_RA_DEBUG_JOIN
      debug_printf("cannot join %i to %i: not allowed\n", b->n, a->n);
#endif
      return;
   }
   if (livei_have_overlap(a->join, b->join)) {
#ifdef NV50_RA_DEBUG_JOIN
      debug_printf("cannot join %i to %i: livei overlap\n", b->n, a->n);
      livei_print(a);
      livei_print(b);
#endif
      return;
   }

   do_join_values(ctx, a, b);
}

static INLINE boolean
need_new_else_block(struct nv_basic_block *b, struct nv_basic_block *p)
{
   int i = 0, n = 0;

   for (; i < 2; ++i)
      if (p->out[i] && p->out_kind[i] != CFG_EDGE_LOOP_LEAVE)
         ++n;

   return (b->num_in > 1) && (n == 2);
}

/* For each operand of each PHI in b, generate a new value by inserting a MOV
 * at the end of the block it is coming from and replace the operand with its
 * result. This eliminates liveness conflicts and enables us to let values be
 * copied to the right register if such a conflict exists nonetheless.
 */
static int
pass_generate_phi_movs(struct nv_pc_pass *ctx, struct nv_basic_block *b)
{
   struct nv_instruction *i, *ni;
   struct nv_value *val;
   struct nv_basic_block *p, *pn;
   int n, j;

   b->pass_seq = ctx->pc->pass_seq;

   for (n = 0; n < b->num_in; ++n) {
      p = pn = b->in[n];
      assert(p);

      if (need_new_else_block(b, p)) {
         pn = new_basic_block(ctx->pc);

         if (p->out[0] == b)
            p->out[0] = pn;
         else
            p->out[1] = pn;

         if (p->exit->target == b) /* target to new else-block */
            p->exit->target = pn;

         b->in[n] = pn;

         pn->out[0] = b;
         pn->in[0] = p;
         pn->num_in = 1;
      }
      ctx->pc->current_block = pn;

      for (i = b->phi; i && i->opcode == NV_OP_PHI; i = i->next) {
         for (j = 0; j < 4 && i->src[j]; ++j) {
            if (nvbb_reachable_by(p, i->src[j]->value->insn->bb, b))
               break;
         }
         if (j >= 4 || !i->src[j])
            continue;
         val = i->src[j]->value;

         ni = new_instruction(ctx->pc, NV_OP_MOV);

         /* TODO: insert instruction at correct position in the first place */
         if (ni->prev && ni->prev->target)
            nv_nvi_permute(ni->prev, ni);

         ni->def[0] = new_value(ctx->pc, val->reg.file, val->reg.type);
         ni->def[0]->insn = ni;
         ni->src[0] = new_ref(ctx->pc, val);

         nv_reference(ctx->pc, &i->src[j], ni->def[0]);
      }

      if (pn != p && pn->exit) {
         ctx->pc->current_block = b->in[n ? 0 : 1];
         ni = new_instruction(ctx->pc, NV_OP_BRA);
         ni->target = b;
         ni->is_terminator = 1;
      }
   }

   for (j = 0; j < 2; ++j)
      if (b->out[j] && b->out[j]->pass_seq < ctx->pc->pass_seq)
         pass_generate_phi_movs(ctx, b->out[j]);

   return 0;
}

static int
pass_join_values(struct nv_pc_pass *ctx, int iter)
{
   int c, n;

   for (n = 0; n < ctx->num_insns; ++n) {
      struct nv_instruction *i = ctx->insns[n];

      switch (i->opcode) {
      case NV_OP_PHI:
         if (!iter)
            continue;
         try_join_values(ctx, i->src[0]->value, i->src[1]->value);
         try_join_values(ctx, i->def[0], i->src[0]->value);
         break;
      case NV_OP_MOV:
         if (iter && i->src[0]->value->insn &&
             !nv_is_vector_op(i->src[0]->value->join->insn->opcode))
            try_join_values(ctx, i->def[0], i->src[0]->value);
         break;
      case NV_OP_SELECT:
         if (!iter)
            break;
         assert(join_allowed(ctx, i->def[0], i->src[0]->value));
         assert(join_allowed(ctx, i->def[0], i->src[1]->value));
         do_join_values(ctx, i->def[0], i->src[0]->value);
         do_join_values(ctx, i->def[0], i->src[1]->value);
         break;
      case NV_OP_TEX:
      case NV_OP_TXB:
      case NV_OP_TXL:
      case NV_OP_TXQ:
         if (iter)
            break;
         for (c = 0; c < 4; ++c) {
            if (!i->src[c])
               break;
            do_join_values(ctx, i->def[c], i->src[c]->value);
         }
         break;
      default:
         break;
      }
   }
   return 0;
}

/* Order the instructions so that live intervals can be expressed in numbers. */
static void
pass_order_instructions(void *priv, struct nv_basic_block *b)
{
   struct nv_pc_pass *ctx = (struct nv_pc_pass *)priv;
   struct nv_instruction *i;

   b->pass_seq = ctx->pc->pass_seq;

   assert(!b->exit || !b->exit->next);
   for (i = b->phi; i; i = i->next) {
      i->serial = ctx->num_insns;
      ctx->insns[ctx->num_insns++] = i;
   }
}

static void
bb_live_set_print(struct nv_pc *pc, struct nv_basic_block *b)
{
#ifdef NV50_RA_DEBUG_LIVE_SETS
   int j;
   struct nv_value *val;

   debug_printf("LIVE-INs of BB:%i: ", b->id);

   for (j = 0; j < pc->num_values; ++j) {
      if (!(b->live_set[j / 32] & (1 << (j % 32))))
         continue;
      val = &pc->values[j];
      if (!val->insn)
         continue;
      debug_printf("%i ", val->n);
   }
   debug_printf("\n");
#endif
}

static INLINE void
live_set_add(struct nv_basic_block *b, struct nv_value *val)
{
   if (!val->insn) /* don't add non-def values */
      return;
   b->live_set[val->n / 32] |= 1 << (val->n % 32);
}

static INLINE void
live_set_rem(struct nv_basic_block *b, struct nv_value *val)
{
   b->live_set[val->n / 32] &= ~(1 << (val->n % 32));
}

static INLINE boolean
live_set_test(struct nv_basic_block *b, struct nv_ref *ref)
{
   int n = ref->value->n;
   return b->live_set[n / 32] & (1 << (n % 32));
}

/* The live set of a block contains those values that are live immediately
 * before the beginning of the block, so do a backwards scan.
 */
static int
pass_build_live_sets(struct nv_pc_pass *ctx, struct nv_basic_block *b)
{
   struct nv_instruction *i;
   int j, n, ret = 0;

   debug_printf("pass_build_live_sets BB:%i\n", b->id);

   if (b->pass_seq >= ctx->pc->pass_seq) {
      debug_printf("already visited\n");
      return 0;
   }
   b->pass_seq = ctx->pc->pass_seq;

   /* slight hack for undecidedness: set phi = entry if it's undefined */
   if (!b->phi)
      b->phi = b->entry;

   for (n = 0; n < 2; ++n) {
      if (!b->out[n] || b->out[n] == b)
         continue;
      ret = pass_build_live_sets(ctx, b->out[n]);
      if (ret)
         return ret;

      if (n == 0) {
         for (j = 0; j < (ctx->pc->num_values + 31) / 32; ++j)
            b->live_set[j] = b->out[n]->live_set[j];
      } else {
         for (j = 0; j < (ctx->pc->num_values + 31) / 32; ++j)
            b->live_set[j] |= b->out[n]->live_set[j];
      }

      /* Kick values out of our live set that are created in incoming
       * blocks of our successors that are not us.
       */
      for (i = b->out[n]->phi; i && i->opcode == NV_OP_PHI; i = i->next) {
         for (j = 0; j < 4; ++j) {
            if (!i->src[j])
               break;
            assert(i->src[j]->value->insn);

            if (nvbb_reachable_by(b, i->src[j]->value->insn->bb, b->out[n])) {
               live_set_add(b, i->src[j]->value);
               debug_printf("BB:%i liveset + %i\n", b->id, i->src[j]->value->n);
            } else {
               live_set_rem(b, i->src[j]->value);
               debug_printf("BB:%i liveset - %i\n", b->id, i->src[j]->value->n);
            }
         }
      }
   }

   if (!b->entry)
      return 0;

   bb_live_set_print(ctx->pc, b);

   for (i = b->exit; i; i = i->prev) {
      for (j = 0; j < 4; j++) {
         if (!i->def[j])
            break;
         live_set_rem(b, i->def[j]);
      }
      for (j = 0; j < 4; j++) {
         if (!i->src[j])
            break;
         live_set_add(b, i->src[j]->value);
      }
      if (i->src[4])
         live_set_add(b, i->src[4]->value);
      if (i->flags_def)
         live_set_rem(b, i->flags_def);
      if (i->flags_src)
         live_set_add(b, i->flags_src->value);
   }
   bb_live_set_print(ctx->pc, b);

   return 0;
}

static void collect_live_values(struct nv_basic_block *b, const int n)
{
   int i;

   if (b->out[0]) {
      if (b->out[1]) { /* what to do about back-edges ? */
         for (i = 0; i < n; ++i)
            b->live_set[i] = b->out[0]->live_set[i] | b->out[1]->live_set[i];
      } else {
         memcpy(b->live_set, b->out[0]->live_set, n * sizeof(uint32_t));
      }
   } else
   if (b->out[1]) {
      memcpy(b->live_set, b->out[1]->live_set, n * sizeof(uint32_t));
   } else {
      memset(b->live_set, 0, n * sizeof(uint32_t));
   }
}

/* NOTE: the live intervals of phi functions start the the first non-phi instruction */
static int
pass_build_intervals(struct nv_pc_pass *ctx, struct nv_basic_block *b)
{
   struct nv_instruction *i, *i_stop;
   int j, s;
   const int n = (ctx->pc->num_values + 31) / 32;

   debug_printf("building intervals for BB %i\n", b->id);

   /* verify that first block does not have live-in values */
   if (b->num_in == 0)
      for (j = 0; j < n; ++j)
         assert(b->live_set[j] == 0);

   collect_live_values(b, n);

   /* remove live-outs def'd in a parallel block, hopefully they're all phi'd */
   for (j = 0; j < 2; ++j) {
      if (!b->out[j] || !b->out[j]->phi)
         continue;
      for (i = b->out[j]->phi; i->opcode == NV_OP_PHI; i = i->next) {
         live_set_rem(b, i->def[0]);

         for (s = 0; s < 4; ++s) {
            if (!i->src[s])
               break;
            assert(i->src[s]->value->insn);
            if (nvbb_reachable_by(b, i->src[s]->value->insn->bb, b->out[j]))
               live_set_add(b, i->src[s]->value);
            else
               live_set_rem(b, i->src[s]->value);
         }
      }
   }

   /* remaining live-outs are live until the end */
   if (b->exit) {
      for (j = 0; j < ctx->pc->num_values; ++j) {
         if (!(b->live_set[j / 32] & (1 << (j % 32))))
            continue;
#ifdef NV50_RA_DEBUG_LIVEI
         debug_printf("adding range for live value %i\n", j);
#endif
         add_range(&ctx->pc->values[j], b, b->exit->serial + 1);
      }
   }
   debug_printf("%s: looping through instructions now\n", __func__);

   i_stop = b->entry ? b->entry->prev : NULL;

   /* don't have to include phi functions here (will have 0 live range) */
   for (i = b->exit; i != i_stop; i = i->prev) {
      assert(i->serial >= b->phi->serial && i->serial <= b->exit->serial);
      for (j = 0; j < 4; ++j) {
         if (i->def[j])
            live_set_rem(b, i->def[j]);
      }
      if (i->flags_def)
         live_set_rem(b, i->flags_def);

      for (j = 0; j < 5; ++j) {
         if (i->src[j] && !live_set_test(b, i->src[j])) {
            live_set_add(b, i->src[j]->value);
#ifdef NV50_RA_DEBUG_LIVEI
            debug_printf("adding range for source that ends living: %i\n",
                         i->src[j]->value->n);
#endif
            add_range(i->src[j]->value, b, i->serial);
         }
      }
      if (i->flags_src && !live_set_test(b, i->flags_src)) {
         live_set_add(b, i->flags_src->value);
#ifdef NV50_RA_DEBUG_LIVEI
         debug_printf("adding range for source that ends living: %i\n",
                      i->flags_src->value->n);
#endif
         add_range(i->flags_src->value, b, i->serial);
      }
   }

   b->pass_seq = ctx->pc->pass_seq;

   if (b->out[0] && b->out[0]->pass_seq < ctx->pc->pass_seq)
      pass_build_intervals(ctx, b->out[0]);

   if (b->out[1] && b->out[1]->pass_seq < ctx->pc->pass_seq)
      pass_build_intervals(ctx, b->out[1]);

   return 0;
}

static INLINE void
nv50_ctor_register_set(struct nv_pc *pc, struct register_set *set)
{
   memset(set, 0, sizeof(*set));

   set->last[NV_FILE_GPR] = 255;
   set->last[NV_FILE_OUT] = 127;
   set->last[NV_FILE_FLAGS] = 4;
   set->last[NV_FILE_ADDR] = 4;

   set->pc = pc;
}

static void
insert_ordered_tail(struct nv_value *list, struct nv_value *nval)
{
   struct nv_value *elem = list->prev;

   // debug_printf("inserting value %i\n", nval->n);

   for (elem = list->prev;
	elem != list && elem->livei->bgn > nval->livei->bgn;
	elem = elem->prev);
   /* now elem begins before or at the same time as val */

   nval->prev = elem;
   nval->next = elem->next;
   elem->next->prev = nval;
   elem->next = nval;
}

static int
pass_linear_scan(struct nv_pc_pass *ctx, int iter)
{
   struct nv_instruction *i;
   struct register_set f, free;
   int k, n;
   struct nv_value *cur, *val, *tmp[2];
   struct nv_value active, inactive, handled, unhandled;

   make_empty_list(&active);
   make_empty_list(&inactive);
   make_empty_list(&handled);
   make_empty_list(&unhandled);

   nv50_ctor_register_set(ctx->pc, &free);

   /* joined values should have range = NULL and thus not be added;
    * also, fixed memory values won't be added because they're not
    * def'd, just used
    */
   for (n = 0; n < ctx->num_insns; ++n) {
      i = ctx->insns[n];

      for (k = 0; k < 4; ++k) {
         if (i->def[k] && i->def[k]->livei)
            insert_ordered_tail(&unhandled, i->def[k]);
         else
         if (0 && i->def[k])
            debug_printf("skipping def'd value %i: no livei\n", i->def[k]->n);
      }
      if (i->flags_def && i->flags_def->livei)
         insert_ordered_tail(&unhandled, i->flags_def);
   }

   for (val = unhandled.next; val != unhandled.prev; val = val->next) {
      assert(val->join == val);
      assert(val->livei->bgn <= val->next->livei->bgn);
   }

   foreach_s(cur, tmp[0], &unhandled) {
      remove_from_list(cur);

      /* debug_printf("handling value %i\n", cur->n); */

      foreach_s(val, tmp[1], &active) {
         if (livei_end(val) <= cur->livei->bgn) {
            reg_release(&free, val);
            move_to_head(&handled, val);
         } else
         if (!livei_contains(val, cur->livei->bgn)) {
            reg_release(&free, val);
            move_to_head(&inactive, val);
         }
      }

      foreach_s(val, tmp[1], &inactive) {
         if (livei_end(val) <= cur->livei->bgn)
            move_to_head(&handled, val);
         else
         if (livei_contains(val, cur->livei->bgn)) {
            reg_occupy(&free, val);
            move_to_head(&active, val);
         }
      }

      f = free;

      foreach(val, &inactive)
         if (livei_have_overlap(val, cur))
            reg_occupy(&f, val);

      foreach(val, &unhandled)
         if (val->reg.id >= 0 && livei_have_overlap(val, cur))
            reg_occupy(&f, val);

      if (cur->reg.id < 0) {
         boolean mem = FALSE;

         if (nv_is_vector_op(cur->insn->opcode))
            mem = !reg_assign(&f, &cur->insn->def[0], 4);
         else
         if (iter)
            mem = !reg_assign(&f, &cur, 1);

         if (mem) {
            NOUVEAU_ERR("out of registers\n");
            abort();
         }
      }
      insert_at_head(&active, cur);
      reg_occupy(&free, cur);
   }

   return 0;
}

int
nv_pc_exec_pass1(struct nv_pc *pc)
{
   struct nv_pc_pass *ctx;
   int i, ret;

   debug_printf("REGISTER ALLOCATION - entering\n");

   ctx = CALLOC_STRUCT(nv_pc_pass);
   if (!ctx)
      return -1;
   ctx->pc = pc;

   nv_print_program(ctx->pc->root);

   ctx->insns = CALLOC(NV_PC_MAX_INSTRUCTIONS, sizeof(struct nv_instruction *));

   pc->pass_seq++;
   ret = pass_generate_phi_movs(ctx, pc->root);
   assert(!ret);

   nv_print_program(ctx->pc->root);

   for (i = 0; i < pc->loop_nesting_bound; ++i) {
      pc->pass_seq++;
      ret = pass_build_live_sets(ctx, pc->root);
      assert(!ret && "live sets");
      if (ret) {
         NOUVEAU_ERR("failed to build live sets (iteration %d)\n", i);
         goto out;
      }
   }

   pc->pass_seq++;
   nv_pc_pass_in_order(pc->root, pass_order_instructions, ctx);

   pc->pass_seq++;
   ret = pass_build_intervals(ctx, pc->root);
   assert(!ret && "build intervals");
   if (ret) {
      NOUVEAU_ERR("failed to build live intervals\n");
      goto out;
   }

#ifdef NV50_RA_DEBUG_LIVEI
   for (i = 0; i < pc->num_values; ++i)
      livei_print(&pc->values[i]);
#endif

   for (i = 0; i < 2; ++i) {
      ret = pass_join_values(ctx, i);
      if (ret)
         goto out;
      ret = pass_linear_scan(ctx, i);
      if (ret)
         goto out;
   }
   assert(!ret && "joining");

   for (i = 0; i < pc->num_values; ++i)
      livei_release(&pc->values[i]);

   debug_printf("REGISTER ALLOCATION - leaving\n");
   nv_print_program(ctx->pc->root);

out:
   FREE(ctx);
   return ret;
}